Siemens SINAMICS G130 Engineering Manual page 124

Fundamental Principles and System Description
Engineering Information
The diagram below shows an example configuration comprising a SINAMICS S120 Infeed in Chassis format at the
beginning of the DC busbar and, arranged to the right of it, S120 Motor Modules in Chassis and Booksize format in
mixed order.
Example of a process-related arrangement of Motor Modules for a drive configuration with SINAMICS S120
Arranging the Motor Modules according to the order of drives in the production process is generally unproblematic if
the following conditions are fulfilled:
·
The output power ratings of the individual Motor Modules do not differ by more than about a factor of 4 to 5.
·
The drive configuration consists only of Motor Modules of one type, i.e. either Chassis or Booksize format.
When these boundary conditions are fulfilled, the process-related arrangement offers practically the same
advantages as the power rating-related option by virtue of the relatively small differences in mechanical dimensions
and electrical ratings between adjacent Motor Modules.
However, in configurations in which the output power ratings of the individual Motor Modules differ by more than a
factor of 5 or Motor Modules in both, Chassis and Booksize format, are mixed in any order, a process-related
arrangement has the following disadvantages:
·
Mounting S120 Motor Modules of Chassis or Booksize format in cabinets can be relatively time-consuming if
the Motor Modules positioned adjacent in the configuration have very different mechanical dimensions,
making it necessary to level out large differences in height or depth between individual Motor Modules.
·
The partitioning required between the Motor Modules in Chassis or Booksize format in order to ensure
optimum guidance of cooling air in the cabinet can be relatively complicated. This is because adjacent Motor
Modules have very different dimensions and cooling air requirements and thus create wide variations in air
pressure. As a result, complicated measures are required to prevent parasitic air circulation inside the
cabinets. For further informatin about cooling air guidance and partitioning, please refer to chapter "General
Engineering Information for SINAMICS", section "Cabinet design and air conditioning".
·
If the S120 Infeed is positioned at one end of the DC busbar and Motor Modules with very high power
outputs at the other end, then it is often necessary to dimension the cross-section of the whole DC busbar
for the full Infeed current of the S120 Infeed. The material costs for the DC busbar can be relatively high as
a result.
·
In the case of a serious defect in a Motor Module with a high power rating (caused, for example, by a
defective IGBT or DC link capacitor), the fuses of a number of adjacent Motor Modules with a low power
rating might also trip in addition to the fuse of the defective Motor Module, requiring a large number of Motor
Module fuses to be replaced as a result.
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Ó Siemens AG